by Alex ⋮ Knowing how much RAM or Memory you need for editing your Photos in Photoshop can be quite tricky at times because there are so many factors to keep in mind.
This is why I have put together this overview guide that will hopefully answer all your questions about RAM/Memory usage when Editing Images.
First of all, the total Memory usage can be split up into 2 main parts:
- How much RAM does your Photo Editing Software need?
- How much RAM does the rest of your typical System need to run stable?
Let’s start with the second one so we have that out of the way.
How much RAM does a typical Computer need to run?
To make this easier, I’ll describe an average Photo Editor’s Computer. It runs Win 10, usually has a browser such as Chrome open with some tabs, an Email Software, and a Windows Photo-Viewer.
Chrome is using 1.3 GByte, the Foto Viewer about 250 MByte, My Email Software another 125 MByte and so on. Let’s take a look what Win 10 uses with only these 3 additional Programs started:
6 GByte of RAM is used, just so the System and some Standard programs can run.
Now that we know how much RAM a typical System uses just to run, I’ll show you how much additional RAM you will need for Photo Editing:
How much RAM does Photoshop need?
This is how can you find out how much RAM you are currently using for Photoshop and how much you will probably need depending on your use case.
After a fresh start of Photoshop, without having any Photos open, the Software itself needs 262MByte of RAM. Start your Task Manager and see for yourself:
Now after opening a 5MByte JPG 12MP 8bpc (bits per channel) Image, my RAM usage increases to 369 MByte.
Why does it increase over 100 MByte? My Image File Size is only about 5 MByte?
Image Compression
Well, the answer is, your Photo Editing Software decompresses any compressed Image File types to make them editable.
JPG is a compressed Image file type, as are PNG and GIF. By using algorithms, the Software can decrease file-size, without losing noticeable Quality. An Image, of course, can only be compressed so much until a quality loss is noticeable.
The reason why a Photo Editing Software decompresses an Image while you edit it is because your photo manipulations are done on a pixel basis, and having to compress the Image after every pixel-change, will make the editing very slow and CPU intensive.
Bit Depth
Another factor for calculating how much RAM you need to edit an uncompressed Image, is Bit Depth.
Typically you edit your Images in RGB mode, meaning you have three channels (R, G, and B) and every channel will be able to save 8 bits or 256 different values. 8 bits per channel, 256 Values per Channel (or Color). All your JPG Images are in 8bpc or 24bpp (bits per pixel).
Resolution
The next important factor, of course, is the Image Resolution. The Math, fortunately, is quite easy:
[Pixel Amount in Width] x [Pixel Amount in Height] x [Bit Depth] x [Number of Channels] divided by 8000000
Why 8 Million? Because 8 Bits are one Byte and a Megabyte are 1000000 Byte.
This will give you the Uncompressed Image Size in MByte that resides in your RAM. If you only have one Layer!
Layers in Photoshop
If you have more than one Layer, you can roughly multiply the amount of RAM usage per Image by the number of Layers.
Also, in Photoshop you can easily find how much RAM your uncompressed Image is currently using by looking in the bottom left corner. The first number is without Layers, the second with all Layers accounted for.
How much Ram do you need for Photoshop?
Ok, this was difficult enough, let’s look at this table, where all Important factors above have already been considered:
| Resolution Megapixel | 8bpc | 10bpc | 16bpc | 32bpc |
|---|---|---|---|---|
| 8MP | 24 MByte | 30 MByte | 48 MByte | 96 MByte |
| 12MP | 36 MByte | 45 MByte | 72 MByte | 144 MByte |
| 16MP | 48 MByte | 60 MByte | 96 MByte | 192 MByte |
| 20MP | 60 MByte | 75 MByte | 120 MByte | 240 MByte |
Great, now you can roughly estimate or calculate how much RAM a single Image will need.
Now, to truly estimate How much RAM you will need for Photo Editing all you have to think about is:
- What Bit Depth do I edit Photos in (usually 8Bpc for JPGs, 16bpc for RAW Files)
- How many Photos do I have open at the same time
- How many Layers do my Photos usually have on average
- How much RAM does my System need additionally
That said, if you don’t want to calculate it yourself but just want some quick recommendation here it is:
On Win 10 and Photoshop, 8 – 16GByte of RAM will be more than enough for most of your tasks when editing JPG Photos in the 10 – 20MP range and the occasional RAW Image.
If you are a power user, that edits mainly in high Bit depths and Resolutions and might have lots of other RAM intensive Software running in the background, consider 16+ GByte of RAM.
That’s about it, have I missed anything? Let me know in the comments.
Good article, however, some changes would be advisable…. In your article you are not taking into account that inactive programs/documents are swapped to disk, and not occupying physical memory. The best way to determine if you need to increase RAM is to monitor the computer’s memory swapping to disk (Rather than trying to calculate the requirement). Using “Resource Monitor” Memory -> Hard Faults/sec, shows this activity. “Resource Monitor” is available from “Task Manager”. Have a nice day 🙂
Hey jie,
Awesome Thanks! Will look into your suggestions and include them in the article.
Cheers!
Alex
I think this is a pretty good way to start … looking at when things with your normal workflow are usually slowing down!
I normally have some youtube music running, along with Lightroom and Photoshop and 8 GB is a total drag, it’s just not enough. When I upgraded to 24 GB I thought it would be too much but apparently LR and PS grab a bit more memory once it’s there and under normal conditions I get close to 20 GB actively being used — but not swapping anymore, so yay.
As a question of principle: are there any disadvantages of getting MORE memory, say 64 GB ?? apart from the cost …
Hey cba,
Some systems such as the Threadripper platform have trouble clocking the RAM at high speeds when all RAM slots are populated. So for example if you had 8x 16gb of ram they would usually only clocks at 2133mhz or 2400mhz but wont be able to clock at 2933mhz. But with 64 GB you don’t have any disadvantages.
Cheers,
Alex
Hello i’m using photoshop for drawing. Currently I draw 12k x 15k resolution. When just opening photoshop file it is using all of my 16gb of ram. I need way more. But not sure how much. Any ideas? Next project will be even bigger.
Hey Martin,
In the bottom left corner of Photoshop there should be an indicator of memory intensive the current file is. What does it say there?
Cheers,
Alex
When i edit in photoshop cs5 (yes, its old af) i edit 4k pictures with tens of layers, and it doesnt take any more than around 100MB of ram.
Same. I’m using Photoshop 6 with 5D Mark IV TIFFs and have zero problems with 8gb ram.
One has to wonder why Chrome needs over a GB of RAM?
As far as I know, general photo editor don’t use more than 8GB of RAM if you don’t deal with really complicated and heavy editing. Obviously, software like Photoshop consumes more resources than something less powerful. These figures depend on the tasks to fulfill.
Hi Alex,
The Photo Editor itself probably won’t use all that much for the average user, thats right. Though knowing how much other software uses up and limits you is good to know. Also think about editing RAW images and lots of them. That can eat into your RAM very fast!
Cheers